Muffler



Pate'nted June 11, 1946 UNITED STATES PATENT OFFICE MUFFLER vCarl Peters, St. Louis, Mo. Application August 10, 19434, Serial No. 548,837

7 claims. 1

This invention relates generally to mutilers or silencers, and more specifically to devices of this type adapted particularly for use in silencing the noises resulting from the operation of internal 'combustion engines, the predominant object of the invention being to provide a muffler of thel type mentioned which, because of its improved construction and arrangement, is capable of performing its intended function in an improved and highly efllcient manner.

Fig. 1 is a longitudinal section of the improved I muiiler of the present invention.

Fig. 2 is a cross-section taken on line 2--2 of Fig. 1.

Fig. 3 is a cross-section taken on line 3-3 of Fig. 1.

Fig. 4 is a cross-section taken on line 4-4 of Fig. 1.

Fig. 5 is a plan view of the improved muiller on a reduced scale.

In the drawing, wherein is shown for purposes of illustration, merely, one embodiment of the invention, A designates the improved muiiler generally. The muiiler A comprises an outer shell l which preferably is tapered and 'curved longitudinally, so as to minimize the resistance of air to the muffler when same isin motion on a moving motor vehicle. At the gas inlet end of the mullier, where the outer shell I is of substantially greater diameter than it is at the opposite, gas discharge end of said mufiier, the shell I is provided with an end wall 2 which preferably is curved as is shown to good advantage in Fig. 1'. The outer shell I is provided with a transverse wall 3 which is spaced longitudinally of said cuterl shell with respect to the end wall 2, said end wall 2, transverse wall 3, and the wall of the outer shell I providing a chamber Within the outer shell.

The end wall 2 has formed therethrough a centrally-located opening through which is extended an inner, gas-inlet tube 4, said inner, gas-inlet tube being projected outwardly beyond the end wall 2 a slight distance, and being extended 1ongitudinally through the chamber between said end wall 2 and the transverse wall 3, and abutting against ,said transverse 'wall 3 so that the rear end of said inner, gas-inlet tube is closed by said transverse wall 3. Also, disposed within the chamber between the end wall 2 and the transverse wall 3 is an intermediate tube 5 which is of substantially greater diameter than the inner, gas-inlet tube 4 and which embraces said inner, gas-inlet tube 4... The opposite ends of the intermediate tube 5 abut against the end wall 2 and the transverse'wall 3, respectively, whereby said opposite ends of said intermediate tube are closed by said end wall and said transverse wall.

Because of the arrangement of the inner, gasinlet tube 4 and the intermediate tube 5 within the outer shell as just described, an annular chamber 6 is provided between the walls of said inner, gas-inlet tube and said intermediate tube, and an annular chamber 1 is provided between the wall of said intermediate tube and the wall of the outer shell. The inner, gasinlet tube 4 has formed through the wall thereof a multiplicity of apertures 8. These apertures are spaced circumferentially and longitudinally of the inner, gas-inlet tube 4, with the apertured portion of the inner, gas-inlet tube starting at a point which is spaced inwardly Vof the end wall 2 some distance, and ending at a point which is spaced some distance from the transverse wall 3, as is shown in Fig. l. Also, in order to obtain a substantial uniform iiow of gases through the apertures throughout the entire length of the apertured portion of the inner, gas-inlet tube 4, the spacings of the apertures are gradually decreased in the direction of the flow of the gases flowing through the inner tube 4 so that the density of the apertures is gradually increased in said drection oi the flow of gases through said inner, gas-inlet tube. The intermediate tube 5 is provided with apertures 9 which are formed through the wall thereof only at the lextreme front end -of said intermediate tube, and, also, the transverse wall 3 has formed therethrough apertures III which are arranged as is shown in Fig. 2 and which communicate only with the annular chamber 'I- of the muiller A.

Disposed within the shell I of the mui'ller A, adjacent to the transverse wall 3, is a second transverse wall II, said transverse walls 3 and II being spaced apart to provide a chamber I2 therebetween. Also, located within the shell l of the muffler at a point spaced longitudinally thereof with respect to the transverse Wall II is a third transverse wall I3. The transverse wall Il is dished, as is shown to good advantage in Fig. 1, and extended from said` transverse wall chamber I2 The opposite end of the inner tube I4 abuts against the transverse wall -I3 so that said tube is closed by said transverse wall at said end thereof, and said inner tube I4 has formed tures I5 which are spaced circumferentially and longitudinally of said inner tube, the apertured portion of said inner tube starting at a point spaced rearwardly of the transverse wall II and ending at a point spaced forwardly from the transverse wall I3 Arranged within the portion of the shell I of the muiiier A. which is located betwe'en the transverse walls II and I3, is an intermediate tube I6 that is disposed in spaced, embracing relation with respect to the inner tube I4 so as to provide within said portion of said shell an annular chamber I1 between the walls of the inner tube Il and the intermediate tube I6, and an annular chamber I8 between the Wall of the intermediate tube I6 and the wall of the shell I Also, the wall of the intermediate tube I6 has formed therethrough apertures I3, which are located only at the extreme front end of said intermediate tube and which place the annular chamber II in communication with the annular chamber I8. It is to be noted that because of the streamlined shape of the shell I of the mufiler A, the Inner tube I4 and the intermediate tube I6 are tapered. with the larger diameters of said tubes being located at the transverse wall II. In the case of the inner tube I4, the tapered shape thereof is important in that it provides for substantially uniform passage of gases through the apertures I5 thereof. throughout the entire length of the apertured portion of said inner tube. the arrangement of the apertures I5 being such that the desired uniform flow of gases is obtained.

The transverse wall I3 is provided with groups of apertures 20 which are formed therethrough in accordance with the arrangement illustrated in Fig. 4. These apertures place the chamber I3 in communication with a discharge chamber 2l that is located rearwardly of the transverse wall I3 and which is provided with an outlet conductor 22. In addition to the apertures 20 the transverse wall I3 is provided with an elongated, arcuate opening 23 which is formed therethrough at its bottom, as is illustrated in Fig. 4. This opening 23 is located immediately adjacent to a bottom portion of the wall of the shell I, and serves a purpose to be hereinafter set forth.

In the operation of the muiller, exhaust gases, issuing from an internal combustion engine with which the muiiler is associated `for use, are discharged through the inner, gas-inlet tube l in the form of successive pressure pulsations and accompanying sound waves. The gases and sound waves pass through the multiplicity of apertures 8 in the wall of the inner, gas-inlet tube I into the annular chamber 6 and are thereby divided into a great number of parts. In the annular chamber 6 the direction of travel of the gases and sound Waves is reversed, and each succeeding part of the many divided parts of gases and sound waves is caused to travel a longer distance to reach the apertures 9 of the intermediate tube 5, than a preceding part discharged Into the chamber 6 through an aperture 8 of the inner, gas-inlet tube 4 which is located closer to said apertures 9. The gases and sound waves are again divided by passage through the apertures 9 1and their direction of ow is again reversed,

`said gases and sound waves traveling rearwardly from the apertures 9 through the annular chamber I and pass through the apertures III in the transverse wall 3, into the chamber I 2. From the chamber I2, the gases and .sound waves travel rearwardly through the inner tube I4 and Dass through the apertures I5 o! said inner tube into the annular chamber I1., said gases and sound waves again being broken up into many parts whose direction of travel is reversed, and said many parts of the gases and sound waves are compelled to travel various distances to reach the apertures I9 at the front end of the intermediate tube I6, as has been previously explained herein in connection with the discharge of gases and sound waves into the space Ii through the apertures 8 of the inner, gas-inlet tube L Upon passing through the apertures I9 into the annular chamber I8 the gases and sound waves are divided into a number of parts and their direction of travel is again reversed, said gases and any remaining modified sound waves finally passing through the apertures 20 and the arcuate opening 23 of the transverse wall I3 into the chamber 2l, and being discharged from said chamber 2I through the outlet conductor 22 to atmosphere.

In the use of theA improved muiiler disclosed herein, the breaking up of the gases and the accompanying sound waves into many parts. and the forcing of the various divided parts of the gases and sound waves to travel various distances in the annular chambers 6 and I1, as has been explained, together with the repeated reversal of the direction of flow of the gases and sound waves, has a very effective silencing eiIect on the sound waves which causes the muffler to perform its intended function in a highly efcient manner.

The function of the elongated, arcuate slot 23, which is formed in the transverse wall I3 of the muiller, is to provide for ridding the interior of the muiiler of moisture which may result from condensation of gases passing through the muier. It is to be noted that this elongated slot is at the extreme lower end of the transverse wall I3, and that the outlet conductor 22 is located at the bottom of the discharge chamber 2l, and as a result of such arrangement any condensate which accumulates in the lower portion of the annular chamber I8 will be blown therefrom by the -force oi the gases being exhausted from the muier through the outlet conductor 22. Additionally, if any condensate should be produced within the annular chamber 'I it will be carried along with the gases passing through` the muifler, such condensate passing through the apertures Ill of the transverse wall 3 into the chamber I2, and through the inner tube Il, and the apertures thereof, into the annular chamber II, and then into the annular chamber I8, from which the condensate is discharged as explained above. The possible presence of condensate within the muffler is the reason for the dished formation of the transverse wall II, as by so shaping said transverse wall I I sharp corners are avoided, and a curved surface is provided along which the moisture may be forced by the gases to the entrance of the inner tube Il. If desired the transverse wall 3 may be provided at its bottom with an opening I0 through which condensate may pass from the annular space I to the chamber I2.

The improved muffler may be assembled in varioug Ways, one of which is to assemble, exteriorly of the outer shell I, the unit comprised of the transverse wall II, the transverse wall I3, the inner tube Il, and the intermediate tube I8, these parts being preferably welded together in their assembled relation. The unit so assembled is passed into the open, larger end of the outer shell, the outer edge of the transverse wall I3 being forced into tight, wedging engagement with the inner face of the wall of the outer shell I. The outer edge of the transverse wall II is then welded to the inner face of the wall of the outer shell with the aid of an elongated gas torch which is passed into the outer shell from the open, larger end thereof. The unit comprised of the transverse wall 3, the end wall 2, the gas inlet tube 4, and the intermediatetube 5, is also assembled exteriorly of the outer shell I, and the parts of said unit are welded together in their assembled relation. This unit is passed into the outer shell I "from the open, larger end of said outer shell, the outer edge of the transverse wall 3 being forced into tight, wedging engagement with the inner face of the wall of the outer shell,

verse wall opposite to the side thereof at which said gas-inlet tube and said intermediate tube are located, apertures formed through said transverse wall in such arrangement that said chamber is placed in communication with the annular space between the wall of said intermediate tube and the wall of said outer shell, and an outlet conductor for the muffler which communicates and the outer edge of the end wall 2 is welded to the edge of the outer shell at the larger end of said outer shell.

While I have described my improved mulller as being well adapted for use in association with internal combustion engines, the invention is not limited to such use, but, instead, may be employed in Various other situations where it is desired to modify and silence sound waves which accompany gases resulting from combustion and explosions.

I claim:

1. A muffler comprising an outer shell, a tapered gas inlet tube extended longitudinally within a portion of said outer shell, a tapered intermediate tube arranged in embracing relation with respect to said gas-inlet tube with the wall of said gas-inlet tube and the wall of said intermediate tube spaced apart to provide an annular space therebetween, the wall of said intermediate tube being spaced from the wall of said outer shell to provide an annular space therebetween, a wall extended transversely of said outer shell within same which closes said gas-inlet tube and said intermediate tube at corresponding ends thereof, the wall of said gas-inlet tube being provided with apertures formed therethrough throughout a substantial portion of the length of said gas-inlet tube, and the wall of said intermediate tube having aperturesformed therethrough at one end only thereof, a chamber located at the side of said transverse wall opposite to the side thereof at which said gas-inlet tube and said intermediate tube are located, apertures formed through said transverse wall in such arrangement that said chamber is placed in communication with the annular space between the wall of said intermediate tube and the wall of said outer shell, and an outlet conductor for the mulller which communicates with said chamber.

2. A muffler comprising an outer shell of tapered formation, a tapered gas inlet tube extended longtudinally within a portion of said outer shell, a tapered intermediate tube arranged in embracing relation with respect to said gasinlet tube with the wall of said gas-inlet tube and the wall of said intermediate tube spaced apart to provide an annular space therebetween, the wall of said intermediate tube being spaced from the wall of said outer shell toprovide an annular space therebetween, a wall extended transversely of said outer shell within same which closes said gas-inlet tube and said intermediate tube at corresponding ends thereof, the wall of said gas-inlet tube being provided with apertures formed therethrough throughout a substantial portion of the length of said gas-inlet tube, and the wall of said intermediate tube having apertures formed therethrough at one end only thereof, a chamber located at the sidel of said transwith said chamber.

3. A muflier comprising an outer shell of tapered formation, a tapered gas inlet tube extended longitudinally within a portion of said outer shell, a tapered intermediate tube arranged in embracing relation with respect to said gasinlet tube with the wall of said gas-inlet tube and the wall of said intermediate tube spaced apart to provide an annular space of tapered shape therebetween, the wall of said intermediate tube being spaced from the wall of said outer shell to provide an annular space of tapered shape therebetween, a wall extended transversely of said outer shell within same which closes said gasinlet tube and said intermediate tube at corresponding ends thereof, the wall of said gas-inlet tube being provided with apertures formed therethrough throughout a substantial portion of the length of said gas-inlet tube, and the wall of said intermediate tube having apertures formed therethrough at one end only thereof, a chamber 1ocated at the side of said transverse wall opposite to the side thereof at which said gas-inlet tube and said intermediate tube are located, apertures formed through said transverse wall in such arrangement that said chamber is placed in communication with the annular space between the wall of said intermediate tube and the Wall of said outer shell, and an outlet conductor for the muffler which communicates with said chamber.

4. A mufiler comprising an outer shell, a gasinlet tube extended longitudinally within a portion of said outer shell, an intermediate tube arranged in spaced relation with respect t0 said gas-inlet tube with the wall of said gas-inlet tube and the wall of said intermediate tube spaced apart to provide an annular space'therebetween,

the wall of said intermediate tube being spaced from lthe wall of said outer shell to provide an annular space therebetween, a wall extended transversely of said outer shell within same which closes correspondingends of said gas-inlet tube and said intermediate tube, the wall of said gasinlet tube being provided with apertures formed therethrough throughout a substantial portion. of the length of said gas-inlet tube, and the wall of said intermediate tube having apertures formed therethrough at one end only thereof, a second transverse wall spaced within said outer shell from the nist-mentioned transverse wall to provide a chamber therebetween and the rstmentioned wall being provided with apertures formed therethrough which place said chamber in communication with the annular space between the wall oi said intermediate tube and the wall of said outer shell, a third transverse wall arranged within said outer shell in spaced relation with respect to the second-mentioned transverse wall, a primary tube disposed within the outer shell in the space between the secondmentioned and the third-mentioned transverse walls and communicating at one of its ends with said chamber, a secondary tube arranged in em bracing relation with respect to said primary tube with the walls of said primary tube and said secondary tube spaced apart to provide an annular space therebetween, the wall of said secondary tube being spaced from the wall of said outer shell to provide an annular space therebetween, said primary tube having apertures formed through the wall thereof throughout a substantial portion of the length of said primary tube, and the wall of said secondary tube having apertures formed therethrough at one end only thereof, and an exhaust compartment formed at the side of said third-mentioned transverse wall opposite to the side thereof at which said primary and secondary tubes are located, said third-mentioned transverse wall closing corresponding ends of said primary and secondary tubes and having apertures formed therethrough which places said exhaust compartment in communication with the annular space between the walls of said secondary tube and said outer shell.

5. A mumer comprising an outer shell, a gasinlet tube extended longitudinally within a portion of said outer shell, an intermediate tube arranged ip spaced relation with respect to said gas-inlet tube with the wall of said gas-inlet tube and the wall of said intermediate tube spaced apart to provide an annular space therebetween, the wall of said intermediate tube being spaced 8 said outer shell to said exhaust compartment for discharge from the muier.

6. A muflier comprising an outer shell. a gasinlet tube extended longitudinally within a portion of said outer shell, an intermediate tube arranged in spaced relation.. with respect to said from the wall of said outer shell to provide an annular space therebetween, a wall extended transversely of said outer shell within same which closes corresponding ends of said gas-inlet tube and said intermediate tube, the wall of said gasinlet tube being provided with apertures formed therethrough throughout a substantial portion of the length of said gas-inlet tube, and the wall, of said intermediate tube having apertures formed therethrough at one end only thereof, a second transverse wall spaced within said outer shell from the first-mentioned transverse wall to provide a chamber therebetween and the rstmentioned wall being provided with apertures formed therethrough which place said chamber in communication with the annular space between the wall of said intermediate tube and the wall of said outer shell, a third transverse wall arranged within said outer shell in spaced relation with respect to the second-mentioned transverse wall, a primary tube disposed within the outer shell in the space between the second-mentioned and the third-mentioned transverse walls and communicating at one oi its ends with said chamber, a secondary tube arranged in. embracing relation with respect to said primary tube with the walls of said primary tube and said secondary tube spaced apart to provide an annular space therebetween, the wall of said secondary tube being spaced from the wall of said outer shell to provide an annular space therebetween, said primary tube having apertures formed through the wall thereof throughout a substantial portion of the length of said primary tube,

'and the wall of said secondary tube having apertures formed therethrough at one end only thereof, and an exhaust compartment formed at the side of said third-mentioned transverse wall opposite to the side thereof at which said primary and secondary tubes are located. said third-mentioned transverse wall closing corresponding ends of said primary and secondary tubes and having apertures formed therethrough which places said exhaust compartment in communication with the annular space between the walls of said secondary tube and said outer shell, and said third-mentioned transverse wall being provided with an opening at its bottom through which condensate may pass from said annular space between the walls of said secondary tube and gas-inlet tube with the wall of said gas-inlet tube and the wall of said intermediate tube spaced apart to provide an annular space therebetween, the wall of said intermediate tube being spaced from the wall of said outer shell to provide an annular space therebetween, a wall e!- tended transversely of said outer shell within same which, closes corresponding ends ol said gas-inlet tubes and said intermediate tube, the wall of said gas-inlet tube being provided with apertures formed therethrough throughout a substantial portion ot the length of said gas-inlet tube, and the wall of said intermediate tube having apertures formed therethrough at one end only thereof, a second transverse wall of dished formation spaced within said outer shell from the first-mentioned transverse wall to provide a chamber therebetween and the first-mentioned wall beingprovided with apertures formed therethrough which place said chamber in communication with the annular space between the wall of said intermediate tube and the wall oi said outer shell, a third transverse wall arranged within said outer shell in spaced relation with respect to the second-mentioned transverse wall, a primary tube disposed within the outer shell in the space between the second-mentioned and the thirdmentioned transverse walls and communicating at one of its ends with said chamber, a secondary tube arranged in embracing relation with respect to said primary tube with the walls of said primary tube and said secondary tube spaced apart to provide an annular space therebetween, the wall of said secondary tube being spaced from the wall of said outer shell to provide an annular space therebetween, said primary tube having apertures formed through the wall thereof throughout a substantial portion of the length of said primary tube, and the wall of said secondary tube having apertures formed therethrough at one end only thereof, and an exhaust compartment formed at the side of said third-mentioned transverse wall opposite to the side thereoi at which said primary and secondary tubes are located, said third-mentioned transverse wall closing corresponding ends of said primary and secondary tubes and having apertures formed therethrough which places said exhaust compartment in communication with the annular space between the walls of said secondary tube and said outer shell, and said ,third-mentioned transverse wall being providedv with an opening at its bottom through which condensate may pass from said annular space betweenthe walls of said secondary tube and said outer shell to said exhaust compartment for discharge from the muiiler.

. 7. A muffler comprising an outer shell, a gaslnlet tube extended longitudinally within a portion of said outer shell, an intermediate tube arranged in spaced relation with respect to said gas-inlet tube with the wall of said gas-inlet tube and the wall of said intermediate tube spaced apart to provide an annular space therebetween, the wall of said intermediate tube being spaced from the wall of said outer shell to provide an annular space therebetween, a wall extended transversely of said outer shell within same which closes corresponding ends of said gas-inlet tube and said intermediate tube, the wall of said gasinlet tube being provided with apertures formed therethrough throughout a substantial portion of the length of said gas-inlet tube, and the wall of said intermediate tube having apertures formed therethrough at one end only thereof, a second transverse wall spaced within said outer shell from -the first-mentioned transverse Wall to provide a chamber therebetween and the rstmentioned wall being providedl with apertures formed therethrough which. place said chamber in communication. with the annular space between the wall of said intermediate tube and the wall of said outer shell, a third transverse wall arranged within said outer shell in spaced relation with respect to the second-mentioned transverse Wall, a primary tube disposed within the outer shell in the space between the secondmentioned and the third-mentioned transverse walls and communicating at one of its ends with said chamber, a secondary tube arranged in embracing relation with respect to said primary tube with the Walls of said primary tube and said secondary tube spaced apart to provide an annular 10 space therebetween, the wall of said secondary tube being spaced from the wall of said outer shell to provide an annular space therebetween, said primary tube having apertures formed through the wall thereof throughout a substantial portion of the length of said primary tube, and the wall of said secondary tube having apertures formed therethrough at one end only thereof, and an exhaust compartment formed at the side of said third-mentioned transverse wall opposite to the side thereof at which said primary and secondary tubes are located, said thirdmentioned transverse wall closing corresPOnding ends of said primary and secondary tubes and having apertures form'ed therethroughl which places said exhaust compartment in communication with the annular space between the Walls of said secondary tube and said outer shell, said outer shell, said primary tube, and Said secondary tube being of tapered formation, and said annular spaces between the Walls of said primary tube, said secondary tube and said outer shell being tapered.

CARL PETERS. 

